Introduction

Aquaculture in the last decade is the food production sector that has grown the most in productive terms worldwide and tilapiculture has achieved the greatest and fastest growth representing 10.3% of the total fish production worldwide being in second place in the world ranking of the most farmed fish species in the world (Cortés-Sánchez et al., 2021Cortés-Sánchez, A. J., Espinosa-Chaurand, L. D., Díaz-Ramirez, M., & Torres-Ochoa, E. (2021). Plesiomonas: A review on food safety, fish‐borne diseases, and tilapia. The Scientific World Journal, 2021(1), 3119958, ISSN: 1537-744X, Publisher: Wiley Online Library. DOI: https://www.doi.org/10.1155/2021/3119958 or PMCID: PMC847891
; FAO, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
; Samaddar, 2022Samaddar, A. (2022). Recent trends on Tilapia cultivation and its major socioeconomic impact among some developing nations: A Review. Asian J. Fish. Aquat. Res, 8, 1-10.
). Tilapiculture is defined as the process of growing fish of the different species of tilapia. This activity which began to be practiced in Egypt and Africa over 4000 years ago, is currently practiced in 5 of the existing six continents namely: in Africa, America, Asia, Europe and Oceania, over 170 countries from 195 countries exist, with tropical, subtropical and temperate climates predominantly in those countries considered low-middle income countries (LMICS) in the south of Africa, Asia and South America (Figure 1), Ke et al. (2012)Ke, X., Lu, M., Gao, F., Zhu, H., & Huang, Z. (2012). Recovery and pathogenicity analysis of Aerococcus viridans isolated from tilapia (Orecohromis niloticus) cultured in southwest of China. Aquaculture, 342, 18-23, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2012.02.012
; McMurtrie et al. (2022)McMurtrie, J., Alathari, S., Chaput, D. L., Bass, D., Ghambi, C., Joseph N, Anacona, J., Mohan, C. V., Cable, J., & Temperton, B. (2022). Relationships between pond water and tilapia skin microbiomes in aquaculture ponds in Malawi. Aquaculture, 558, 738367, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2022.738367 ,
, where in general the largest producers are the Asians. In Africa, tilapia is the most produced species representing 57.02% of aquaculture production (Figure 1), (FAO, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
).

Current state of tilapiculture and productive projection

Already named as the “aquatic chicken” by international development agencies in the 1970s and as the fish of the 1990s in the 1990s, it is currently considered as the fish of the 21st century presenting itself as the revelation star of aquaculture (Prabu et al., 2019Prabu, E., Rajagopalsamy, C., Ahilan, B., Jeevagan, I., & Renuhadevi, M. (2019). Tilapia-an excellent candidate species for world aquaculture: A review. Annual Research & Review in Biology, 31(3), 1-14, Publisher: Sciencedomain International.
). The tilapia production is increasing over the last eight decades 1950-2018 reaching its maximum global production record in 2018 where production of 6,882. 202 tons and the growth perspective of this sector is global with the highest growth rate in the coming years in African countries in the range of 60% and a production projection that foresees the doubling of the global production of tilapia by 2030 in relation to its 2010 global production making it one of the leading fish and tilapiculture a key element in the future development of aquaculture and an important factor in meeting some of the UN-FAO challenges within its strategic plan for sustainable development 2020-2030 aimed at ending hunger and poverty in all its forms, achieve improved food security and nutrition, promote sustainable agriculture, ensure healthy lives, promote well-being at all ages, ensure availability and sustainable management of water and sanitation for all, ensure sustainable consumption and production patterns (FAO, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
; Samaddar, 2022Samaddar, A. (2022). Recent trends on Tilapia cultivation and its major socioeconomic impact among some developing nations: A Review. Asian J. Fish. Aquat. Res, 8, 1-10.
; United Nations, 2020United Nations. (2020). Agenda for Sustainable Development. Transforming our world. A/RES/70/1. https://wedocs.unep.org/20.500.11822/9814
).

Currently, tilapia is produced in most countries for self-consumption by thousands of small-scale farmers who supplement their diet with tilapia and in proportion to production, the largest consumers of tilapia are the Asians where it is also a commodity for China, Israel and Brazil who are the largest exporters of tilapia in the world marketing it to African, European and American countries FAO (2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020b)FAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
; Prabu et al. (2019)Prabu, E., Rajagopalsamy, C., Ahilan, B., Jeevagan, I., & Renuhadevi, M. (2019). Tilapia-an excellent candidate species for world aquaculture: A review. Annual Research & Review in Biology, 31(3), 1-14, Publisher: Sciencedomain International.
; Toguyeni (2004)Toguyeni, A. (2004). Tilapia production and its global impacts in Central African countries. Institut du développement rural, université polytecchnique de Bobo-dioulasso 01 BP 1091, 01 Burkina Faso. https://ag.arizona.edu/azaqua/ista/ista6/ista6web/pdf/691.pdf
and in these countries the tilapia production industry is not seen as an alternative to fighting hunger and poverty but as a big corporate business. In parallel to production the economic value of tilapia has grown globally where the average kilogram price increased by USD 0.5 in 2018 compared to the kilogram price in 2010, with the kilogram price increasing from USD 1.36 to USD 1.86. This global average price varied positively and negatively when evaluated by regions with appreciation above 0.5 USD in developed countries where the price increased from 3.46 to 5.72 USD/kg in a change of 2.25 USD/kg and depreciation in developing countries where the global average price of the kilogram decreased by 0.05 USD having gone from 1.98 USD/kg to 1.93 USD/kg (FAO, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
). The growth and yields of tilapia farming in recent years are shown in Figure 2.

Similar to the productive level and market price, tilapiculture has also been growing in the production systems used. The production methods adopted vary from country to country and various systems and means of production have been used according to the country's production level, existing legislation on availability and use of water and land resources, environmental factors in the country, climatic conditions, innovation, accessibility, technological availability, skilled labour, level of knowledge, food availability, financing and production support. Thus, based on the above factors, tilapia has been produced using the systems shown in Table 1.

Food, nutritional, employment and income need in the world only tend to increase with the growth of global population density and the worsening of environmental conditions that make the food production process difficult and tilapiculture presents itself as the food sector in the opposite direction of the general scenario.

Since tilapicultura produces meat of high protein value besides being a source of employment and an important element for rural development and the generation of livelihood and income for families mainly in developing countries.

The development of new strains or the introduction of GIFT (Genetically Improved Farmed Tilapia) tilapia that have better records in terms of production, health and physical, nutritional quality is also the trend for the coming years (Samaddar, 2022Samaddar, A. (2022). Recent trends on Tilapia cultivation and its major socioeconomic impact among some developing nations: A Review. Asian J. Fish. Aquat. Res, 8, 1-10.
).

Normally, it is cultivated for human food as well as for feeding carnivorous fish species that are cultured such as sea bass, mud snail in India, while quo in Brazil the possibilities in the treatment of burns to improve the healing process of burns is studied in Brazil (De Miranda, 2018De Miranda, B. M. J. (2018). Viabilidade da pele de Tilápia do Nilo (Oreochromis niloticus) como curativo biológico no tratamento de queimaduras: Revisão da literatura. Anais da faculdade de medicina de olinda, 1(1), 49-52, ISSN: 2674-8487.
).

Tilapia species produced in tilapiculture worldwide

Originating from Africa, tilapia corresponds to a family of freshwater fish composed of 112 species and subspecies grouped into three genera according to their parental behaviour: genus Tilapia, genus Sarotherodon and genus Oreochromis (Machimbirike et al., 2019Machimbirike, V. I., Jansen, D. M., Senapin, S., Khunrae, P., Rattanarojpong, T., & Dong, H. T. (2019). Viral infections in tilapines: More than just tilapia lake virus. Aquaculture, 503, 508-518, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.aquaculture.2019.01.036
; Prabu et al., 2019Prabu, E., Rajagopalsamy, C., Ahilan, B., Jeevagan, I., & Renuhadevi, M. (2019). Tilapia-an excellent candidate species for world aquaculture: A review. Annual Research & Review in Biology, 31(3), 1-14, Publisher: Sciencedomain International.
). Of these existing varieties, in current tilapiculture only 23 species are bred and species of the genus Oreochromis are the most cultivated because they tolerate better high stocking densities, grow faster, disease resistance, are adapted to captivity, accept balanced diets, and have good quality meat and therefore are well accepted in the market Cortés-Sánchez et al. (2021)Cortés-Sánchez, A. J., Espinosa-Chaurand, L. D., Díaz-Ramirez, M., & Torres-Ochoa, E. (2021). Plesiomonas: A review on food safety, fish‐borne diseases, and tilapia. The Scientific World Journal, 2021(1), 3119958, ISSN: 1537-744X, Publisher: Wiley Online Library. DOI: https://www.doi.org/10.1155/2021/3119958 or PMCID: PMC847891
and among the 23 species bred, only 10 species are commercially important worldwide in which the following stand out in order of highest production in Tables 2, 3, 4 and 5: These species which have a productive potential, together contributed less than 1% of the total world tilapia production. and the predominant species in terms of production and world distribution is Oreochromis niloticus (Albuquerque et al., 2015Albuquerque, D. M., Albuquerque, D. M., Marengoni, A. N. G., Mahal, I., de Moura, M. C., Rodíguez-Rodíguez, M. P., Galo, J. M., & Ribeiro, R. R. (2015). Bacillus em dietas para alevinos de tilápia do nilo, variedade gift. Bioscience journal. DOI: http://dx.doi.org/10.14393/BJ-v31n2a2015-22506
.; Machimbirike et al., 2019Machimbirike, V. I., Jansen, D. M., Senapin, S., Khunrae, P., Rattanarojpong, T., & Dong, H. T. (2019). Viral infections in tilapines: More than just tilapia lake virus. Aquaculture, 503, 508-518, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.aquaculture.2019.01.036
; Prabu et al., 2019Prabu, E., Rajagopalsamy, C., Ahilan, B., Jeevagan, I., & Renuhadevi, M. (2019). Tilapia-an excellent candidate species for world aquaculture: A review. Annual Research & Review in Biology, 31(3), 1-14, Publisher: Sciencedomain International.
; Samaddar, 2022Samaddar, A. (2022). Recent trends on Tilapia cultivation and its major socioeconomic impact among some developing nations: A Review. Asian J. Fish. Aquat. Res, 8, 1-10.
).

Diseases in tilapiculture

With the growth, expansion and intensification of aquaculture production, biosecurity becomes an important consideration as aquatic animal diseases are one of the most serious constraints to the expansion and sustainable development of aquaculture (FAO, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
). Intensification can cause chronic stress that adversely impacts fish physiology resulting in reduced growth and resilience to disease. Increasing stocking density and production levels often occur with insufficient clean water, leading to deterioration in water quality, including dissolved oxygen, hydrogen potential (pH) and ammonia, which in turn negatively impacts fish growth and health and leaves them more susceptible to disease (McMurtrie et al., 2022McMurtrie, J., Alathari, S., Chaput, D. L., Bass, D., Ghambi, C., Joseph N, Anacona, J., Mohan, C. V., Cable, J., & Temperton, B. (2022). Relationships between pond water and tilapia skin microbiomes in aquaculture ponds in Malawi. Aquaculture, 558, 738367, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2022.738367 ,
).

Globally, a trend in aquaculture is that previously unreported pathogens causing new and unknown diseases emerge and spread rapidly causing increased production losses approximately every 3 to 5 years, in addition to endemic diseases in each region with local losses and impacts (FAO, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
). Such diseases are mostly caused by viruses but globally in several occurrences the etiological agents reported have been bacteria, parasites and fungi (FAO, 2020aFAO. (2020a). The State of World Fisheries and Aquaculture 2020 (p. DOI: https://www.doi.org/10.4060/ca99292en) . Sustainability in action. Rome, Italy. https://www.fao.org
, 2020bFAO. (2020b). Tilapia production and trade with a focus on India. WAPI factsheet to facilitate evidence-based policy-making and sector management in aquaculture. https://www.fao.org
). Like any production system, tilapia farming is susceptible to disease.

Tilapia has long been considered a disease-resistant species because of its high tolerance to a wide temperature range, its survival in different salinities and environmental conditions considered adverse and its lower climatic and environmental requirements compared to other farmed fish species. Currently, this knowledge is held as an outdated belief because recent studies point out that the disappointment of intensive tilapia production has made it more susceptible to disease-causing microorganisms McMurtrie et al. (2022)McMurtrie, J., Alathari, S., Chaput, D. L., Bass, D., Ghambi, C., Joseph N, Anacona, J., Mohan, C. V., Cable, J., & Temperton, B. (2022). Relationships between pond water and tilapia skin microbiomes in aquaculture ponds in Malawi. Aquaculture, 558, 738367, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2022.738367 ,
and all other factors related to the emergence of diseases.

Disease is a condition in living organisms in which normal physiological functions are impaired by changes in body systems and typically manifested by distinct signs and symptoms. As in all animals in a cultured environment, for the emergence of a disease in tilapiculture there must be the interaction of several factors related and integrated in the pathogenic triad presented in Figure 3.

In tilapia as in every animal the diseases are classified based on the origin of the disease into two major groups infectious and non-infectious which in turn aggregate different diseases that are given specific names based on the causative agent of the same as presented in Table 5, being the infectious diseases that constitute the greatest challenging problems for tilapicultura, public health and food safety (Abdelsalam et al., 2023Abdelsalam, M., Elgendy, M. Y., Elfadadny, M. R., Ali, S. S., Sherif, A. H., & Abolghait, S. K. (2023). A review of molecular diagnoses of bacterial fish diseases. Aquaculture International, 31(1), 417-434, ISSN: 0967-6120, Publisher: Springer. DOI: https://doi.org/10.1007/s10499-022-00983-8
; Journal of environmental science and technology, 2020; Rahman Md Ashikur et al., 2019Rahman Md Ashikur, Akter, S., Khan, M. M., & Rahman, M. K. (2019). Relation between aquaculture with fish disease & health management: A review note. Bangladesh Journal of Fisheries, 31(2), 253-260.
).

Frequency of disease occurrence in tilapia production

In recent times, tilapia farming has been burdened with diseases and other problems caused by viruses, bacteria, parasitic fungi and other unidentified or emerging pathogens Bondad-Reantaso et al. (2005)Bondad-Reantaso, M., Subasinghe, R. P., Arthur, J. R., Ogawa, K., Chinabut, S., Adlard, R., Tan, Z., & Shariff, M. (2005). Disease and health management in Asian aquaculture. Veterinary parasitology, 132(3-4), 249-272, ISSN: 0304-4017, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.vetpar.2005.07.005
although recording and reporting of occurrences has been a problem for some of the major producers such as Asian countries that under-report disease occurrences as well as African countries that do not report due to lack of material technical conditions, information, training and technical assistance. Bacterial infections are common in tilapicultura in Egypt that several cases arise mixed infections where more than one infectious agent co-infect the fish (Abdelsalam et al., 2023Abdelsalam, M., Elgendy, M. Y., Elfadadny, M. R., Ali, S. S., Sherif, A. H., & Abolghait, S. K. (2023). A review of molecular diagnoses of bacterial fish diseases. Aquaculture International, 31(1), 417-434, ISSN: 0967-6120, Publisher: Springer. DOI: https://doi.org/10.1007/s10499-022-00983-8
).

With intensification and increase in production the incidence of diseases has also increased in a directly proportional reaction (Ali et al., 2020Ali, S. E., Jansen, M. D., Mohan, C. V., Delamare-Deboutteville, J., & Charo-Karisa, H. (2020). Key risk factors, farming practices and economic losses associated with tilapia mortality in Egypt. Aquaculture, 527, 735438, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2020.735438
). Despite insufficiency in statistical data, publications indicate that in Asian countries such as Thailand, where intensification is established and on a large scale, outbreaks of unknown diseases occur annually with mortalities above 50% (Dong et al., 2015Dong, H. T., Nguyen, V. V., Le, H. D., Sangsuriya, P., Jitrakorn, S., Saksmerprome, V., Senapin, S., & Rodkhum, C. (2015). Naturally concurrent infections of bacterial and viral pathogens in disease outbreaks in cultured Nile tilapia (Oreochromis niloticus) farms. Aquaculture, 448, 427-435, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2015.06.027
).

Main diseases reported

The diseases reported in tilapiculture are mainly those of infectious origin among which are viral, bacterial, parasitic and fungal infectious diseases in which most dermal diseases are caused by the parasitic bacteria and fungi. In turn, bacterial diseases in tilapia are classified into septicaemia bacterial diseases, localized skin diseases and chronic granulomatous diseases (Junior et al., 2020Junior, F. J. A., Leal, G. C. A., de Oliveira, F. T., Nascimento, A. K., de Macêdo, S. J. T., & Pedroso, O. P. M. (2020). Anatomopathological characterization and etiology of lesions on Nile tilapia fillets (Oreochromis niloticus) caused by bacterial pathogens. Aquaculture, 526, 735387, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.or/101016/j.aquaculture.2020.735387
; Leira et al., 2016Leira, H. M., Lago, A. A., Botelho, A. H., Melo, C., Mendonça, F., Nascimento, A., & Freitas, R. (2016). Principais infecções bacterianas na criação de peixes de água doce do Brasil-uma revisão. Revista de Ciência Veterinária e Saúde Pública, 3(1), 44-59. DOI: https://www.doi.org/10.4025/revcivet.v3i1.32436
). The diseases recorded in tilapiculture are shown in Table 6.

Pathogens involved in the occurrence of such diseases

In tilapiculture, tilapias have been affected by different pathogens many already identified some of which are part of their natural microbiota such as some bacteria (Machimbirike et al., 2019Machimbirike, V. I., Jansen, D. M., Senapin, S., Khunrae, P., Rattanarojpong, T., & Dong, H. T. (2019). Viral infections in tilapines: More than just tilapia lake virus. Aquaculture, 503, 508-518, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.aquaculture.2019.01.036
). The main agents implicated in reported cases of disease in tilapia are presented in Table 7.

Impact of disease on tilapia production

Diseases are currently the first limitation in tilapiculture in developed countries and the second in developing countries only behind food shortages due to food insufficiency that promotes competitiveness between food consumption in fish production and human food consumption, preventing growth and economic and social sustainability of production and the country through direct losses in productivity, increased operating costs and indirectly through trade restrictions (Bondad-Reantaso et al., 2005Bondad-Reantaso, M., Subasinghe, R. P., Arthur, J. R., Ogawa, K., Chinabut, S., Adlard, R., Tan, Z., & Shariff, M. (2005). Disease and health management in Asian aquaculture. Veterinary parasitology, 132(3-4), 249-272, ISSN: 0304-4017, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.vetpar.2005.07.005
). The impacts are felt through the expenses necessary to treat the disease once it is installed in production, the loss of dead fish that will reduce the volume of production and consequently affect the financial income to be obtained at the end of the production cycle, which in turn may become a social problem by leading to the loss of jobs in the sector due to low productivity. Diseases in tilapiculture limit productivity and sustainability with impacts on food security, food confidence, job stability and human health. Acute bacterial diseases for example cause massive deaths in a short time as in the case of streptococcosis which leads to considerable morbidity and mortalities worldwide with excessive economic losses which in 2008 form evaluated at over $250 million (Abdelsalam et al., 2023Abdelsalam, M., Elgendy, M. Y., Elfadadny, M. R., Ali, S. S., Sherif, A. H., & Abolghait, S. K. (2023). A review of molecular diagnoses of bacterial fish diseases. Aquaculture International, 31(1), 417-434, ISSN: 0967-6120, Publisher: Springer. DOI: https://doi.org/10.1007/s10499-022-00983-8
; Zamri-Saad et al., 2014Zamri-Saad, M., Amal, M., Siti-Zahrah, A., & Zulkafli, A. (2014). Control and prevention of streptococcosis in cultured tilapia in Malaysia: A review.https://www.pertanika.upm.edu.my/
). The major negative impact of the diseases is the threat to food security and public health that they pose since tilapia can become a potential source of disease to humans.

Identification of diseases in tilapia production units

The identification of diseases in farms follows a diagnostic protocol with staged practices that range from the simplest to the most complex until a precise and definitive diagnosis of the disease-causing agent is reached. In general, producers, researchers and specialists cooperate in the diagnosis of diseases and adopt the diagnostic protocol recommended by FAO and ANACA in which diseases are diagnosed at 3 different and complementary levels:

The three levels of disease identification in production units and tilapia presented, have wide application in disease diagnosis and detention but are not applied to the same extent everywhere. Each country applies one of the levels or a combination of two or all three jointly according to material, technical and professional capacities and availability of resources (Bondad-Reantaso et al., 2005Bondad-Reantaso, M., Subasinghe, R. P., Arthur, J. R., Ogawa, K., Chinabut, S., Adlard, R., Tan, Z., & Shariff, M. (2005). Disease and health management in Asian aquaculture. Veterinary parasitology, 132(3-4), 249-272, ISSN: 0304-4017, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.vetpar.2005.07.005
).

Therapies and prevention

Once the disease is established it can be controlled to reduce or eliminate the source of infection by severing the connection between the infectious source and the fish, reducing the susceptibility of the fish to infection by applying accurate diagnostic techniques and determining the spreading disease methods and interrupting them. In response to the occurrence of disease and death in tilapia culture, the most common immediate action is to stop feeding the fish, collect and remove dead carcasses, increase water flow or change the water if the water salinity is low. Few producers resort to the veterinary services to help solve the problem the most practiced is the self-administration of some chemicals or disinfectants without prescription from antibiotics, biotherapeutics, probiotics, bio remediators, prebiotics phytotherapy and some homemade recipes (Ali et al., 2020Ali, S. E., Jansen, M. D., Mohan, C. V., Delamare-Deboutteville, J., & Charo-Karisa, H. (2020). Key risk factors, farming practices and economic losses associated with tilapia mortality in Egypt. Aquaculture, 527, 735438, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2020.735438
; Journal of environmental science and technology, 2020Journal of environmental science and technology. (2020). A review article on diseases of Nile tilapia with special emphasis on water pollution. Journal of environmental science and technology. DOI: https://www.doi.10.3923/jest.2020.29.56
). Although the global trend is to avoid the use of antibiotics in aquaculture production including tilapiculture aiming to avoid drug residues in the fish fillet and that may cause harm to consumers as well as to reduce the high rate of antibiotic resistance currently faced (Desbois et al., 2021Desbois, A. P., Garza, M., Eltholth, M., Hegazy, Y. M., Mateus, A., Adams, A., Little, D. C., Høg, E., & Mohan, V., C. V. (2021). Systems-thinking approach to identify and assess feasibility of potential interventions to reduce antibiotic use in tilapia farming in Egypt. Aquaculture, 540, 736-735, ISSN: 0044-8486, Publisher: Elsevier. DOI: https://www.doi.org/10.1016/j.aquaculture.2021.736735
) The most commonly applied chemical compounds are presented in Table 8.

The primary aspect to consider in the prevention of disease in tilapicultura is the elimination of predisposing factors since the absolute majority of pathogens are opportunistic and cause epizootic outbreaks associated with predisposing stress factors such as: abrupt drop or rise in water temperature, stock handling , degradation of water quality parameters, introduction of unquarantined fish stock, uncontrolled water source, high stocking density, poor hygiene, high amounts of organic material in the ponds, inadequate aeration, food quality and availability, incorrect location of the farm with poor access roads and electrical supply (Cortés-Sánchez et al., 2021Cortés-Sánchez, A. J., Espinosa-Chaurand, L. D., Díaz-Ramirez, M., & Torres-Ochoa, E. (2021). Plesiomonas: A review on food safety, fish‐borne diseases, and tilapia. The Scientific World Journal, 2021(1), 3119958, ISSN: 1537-744X, Publisher: Wiley Online Library. DOI: https://www.doi.org/10.1155/2021/3119958 or PMCID: PMC847891
; Prabu et al., 2019Prabu, E., Rajagopalsamy, C., Ahilan, B., Jeevagan, I., & Renuhadevi, M. (2019). Tilapia-an excellent candidate species for world aquaculture: A review. Annual Research & Review in Biology, 31(3), 1-14, Publisher: Sciencedomain International.
; Zamri-Saad et al., 2014Zamri-Saad, M., Amal, M., Siti-Zahrah, A., & Zulkafli, A. (2014). Control and prevention of streptococcosis in cultured tilapia in Malaysia: A review.https://www.pertanika.upm.edu.my/
). Therefore, some preventive practices have been applied by producers either totally or partially according to each context to avoid, limit the disease-promoting effects of predisposing factors are proposed in the different international codes, agreements and voluntary or mandatory guides that implemented provide a certain level of protection against pathogens and the occurrence of outbreaks as are the OIE aquatic animal health code, the code of practice and procedure manual for consideration of introductions and transfer of marine and freshwater organisms, and the FAO code of conduct for responsible fishing. There are also country-specific regional regulations according to the specific legislation and problems of each country. Among the various strategic measures for sustainable production and biosecurity the actions taken involve (Journal of environmental science and technology, 2020Journal of environmental science and technology. (2020). A review article on diseases of Nile tilapia with special emphasis on water pollution. Journal of environmental science and technology. DOI: https://www.doi.10.3923/jest.2020.29.56
):

A measure recommended by Zamri-Saad et al. (2014)Zamri-Saad, M., Amal, M., Siti-Zahrah, A., & Zulkafli, A. (2014). Control and prevention of streptococcosis in cultured tilapia in Malaysia: A review.https://www.pertanika.upm.edu.my/
, is seasonal cultivation which consists of stopping cultivation during the hottest season that corresponds to the most critical period for favouring the disappointment of infectious diseases and maintaining cultivation only in the months with temperate environmental conditions, the latter being considered a drastic measure.

Vaccination is a preventive method that has been developed for some diseases in tilapia culture. Currently for example there are vaccines available against vibrioses, furunculosis, enteric red mouth disease and streptococcosis (Bondad-Reantaso et al., 2005Bondad-Reantaso, M., Subasinghe, R. P., Arthur, J. R., Ogawa, K., Chinabut, S., Adlard, R., Tan, Z., & Shariff, M. (2005). Disease and health management in Asian aquaculture. Veterinary parasitology, 132(3-4), 249-272, ISSN: 0304-4017, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.vetpar.2005.07.005
; Journal of environmental science and technology, 2020Journal of environmental science and technology. (2020). A review article on diseases of Nile tilapia with special emphasis on water pollution. Journal of environmental science and technology. DOI: https://www.doi.10.3923/jest.2020.29.56
; Su & Su, 2018Su, H., & Su, J. (2018). Cyprinid viral diseases and vaccine development. Fish & shellfish immunology, 83, 84-95, ISSN: 1050-4648, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.fsi.2018.09.003
).

Diagnosis, information and technology are others strategies presented because the rapid identification of pathogens in asymptomatic fish or in the beginning of infectious process is a preventive measure of disease occurrence fundamental in helping producers in developing biosecurity programs (Abdelsalam et al., 2023Abdelsalam, M., Elgendy, M. Y., Elfadadny, M. R., Ali, S. S., Sherif, A. H., & Abolghait, S. K. (2023). A review of molecular diagnoses of bacterial fish diseases. Aquaculture International, 31(1), 417-434, ISSN: 0967-6120, Publisher: Springer. DOI: https://doi.org/10.1007/s10499-022-00983-8
).

Thus, the application of good management practices, training farmers in observing general signs of diseases in fish and the existence of a linkage with official organs for assistance is the key factor in disease prevention in tilapiculture.

Main difficulties in disease management in tilapia production units

There are several difficulties faced by the tilapia production units in the management of diseases and this includes the increase and globalization of trade and markets; the intensification of productive practices by the movement of reproducers, post larvae, larvae, juveniles and other intermediated commodity movements that cause and maintain local, regional and transboundary diseases; the interaction between farmed and wild populations; poor or non-existent biosecurity parameters; poor awareness of emerging diseases; lack of knowledge of endemic pathogens in global and local tilapia farming; difficulties diagnostics at all diagnostic levels; little confirmation diagnosis; lack of technical and institutional assistance; indiscriminate use (self-treatment) of conventional and natural therapeutic substances applied in the treatment of diseases in tilapia farming due to inexperience of producers and climate changes (Bondad-Reantaso et al., 2005Bondad-Reantaso, M., Subasinghe, R. P., Arthur, J. R., Ogawa, K., Chinabut, S., Adlard, R., Tan, Z., & Shariff, M. (2005). Disease and health management in Asian aquaculture. Veterinary parasitology, 132(3-4), 249-272, ISSN: 0304-4017, Publisher: Elsevier. DOI: https://doi.org/10.1016/j.vetpar.2005.07.005
; Zamri-Saad et al., 2014Zamri-Saad, M., Amal, M., Siti-Zahrah, A., & Zulkafli, A. (2014). Control and prevention of streptococcosis in cultured tilapia in Malaysia: A review.https://www.pertanika.upm.edu.my/
).

Conclusions

Tilapiculture is currently the most expanded fish production worldwide, with the largest global production in territorial terms and with a projection perspective for the next 10 years that guarantees that tilapiculture is the bet for supplying the existing need for good quality animal protein, optimising the exploitation of fishing resources that have been overexploited and destroyed by climate change in recent years, and is an ally in the fight against hunger, poverty, unemployment and underdevelopment of rural populations and localities such as in Africa, Sul and Latin America, and many Asiatic countries. The industry has been affected with outbreaks of viral, bacterial, parasitic and fungal diseases all over the world with mortalities and productive losses that threaten the sustainability and the security of the industry in the future, making necessary the improvement and the incentive to the application of measures, practices and strategies of productive growth and intensified biosecurity guaranteeing its sustainable development.

References